This study is to determine if ciliary neurotrophic factor (CNTF) is useful in treating spinal muscular atrophy (Wernig Hoffman Disease, Kugelberg- Welander Disease). This was the first clinical trial of this medication in children with this disease. It was to determine whether or not CNTF can improve strength or slow the progression of spinal muscular atrophy during a 9-month period of treatment. It will be determined whether this medication produces any acute toxicity or side effects in children with this disease.